This invention provides a unique bi-directional fluid valve apparatus which has widespread utility and is especially adaptable, among other applications, to a double acting simplex plunger pump of the type disclosed in prior U.S. Pat. Nos. 5,173,039 and 5,183,396, the disclosures of which are incorporated herein by reference. Both of these patents, in FIG. 11 thereof, disclose check valves 66, and FIG. 4 thereof show check valves 66 and 67 arranged in reversed senses to provide bi-directional valving function. Check valves 66 and 67 are relatively expensive in comparison to the unique check valve provided by the instant application.
The present invention provides an improved reversible check valve for bi-directional fluid valve apparatus and has the following advantages over the check valves 66 and 67 shown in U.S. Pat. Nos. ""039 and ""396: The prior art check valves had adequate functionality but the four parts thereof made them relatively expensive, at least twenty (20) times more expensive than the unique check valve taught by this application, which is also characterized by its incredible simplicity, reversibility, versatility, quicker response, efficiency, quietness of operation, and adaptability to provide variations in the rate of flow of fluids therethrough by having a family of valve members, each member having a different preselected axial length so as to vary the axial travel of the member and thus accommodate a predetermined flow, or vary the flow rate of fluid passing through the valve.
In broad terms, the present invention provides a reversible bi-directional fluid valve apparatus to be used in combination with a head member having a flat manifold-engaging surface and a manifold member having a flat surface. The two members are connected together with the flat surfaces in abutting relationship. Each of the members has an identical bore therein substantially normal to the abutting flat surfaces, the bores being in axial alignment and each of the members having an identical recess around its respective bore and defining a shoulder having an axial end surface spaced from the abutting surfaces the same preselected distance. The shoulders have identical preselected transverse dimensions. The valve apparatus further comprises a valve member having two axial ends with a flat surface on a first of said axial ends with preselected transverse dimensions greater than said preselected transverse dimensions of the shoulders, positioned with said flat surface thereof abutting the axial end surface of one of the shoulders. The valve member further includes at least two axially extending and circumferentially spaced apart ribs on a second axial end thereof. Each of the ribs is of the same preselected axial length and terminates in an end surface. The ribs are positioned so that the end surfaces thereof are in axial alignment with. and are spaced a preselected distance from, the axial end surface of the other of the shoulders. The valve apparatus further comprises hollow coil spring means positioned within said recesses in register with the bores and having two ends: a first end sized to engage the other shoulder, and a second end of identical dimension sized to engage said second axial end of the valve member above the ribs. The spring means is selected so that it will bias the flat surface of the valve member towards the axial end surface of one of the shoulders so as to provide a closed valve function. Further, the spring is selected so as to yield under applied force to permit axial travel of the valve a limited distance to a position whereat said end surfaces of said ribs are in engagement with the axial end surface of the other shoulder, to provide an open valve function of predetermined area.
The foregoing valve apparatus in a more limited sense is characterized by the bores, recesses, shoulders and valve member all having a circular cross section and the spring means being cylindrical with a circular cross section.
In a more limited sense, my unique valve apparatus is provided in combination with a double acting simplex plunger pump apparatus to provide an improved pump.